199:
with base altitudes 4,600–4,900 metres (15,100–16,100 ft). The complex is split into a northern group encompassing Cerro
Chascon and three other domes (named Cerro Guichi, Morro Chascoso and Pabelloncita Loma), and a southern group of six domes. Their orientation in northwestward direction is
498:
Watts, Robert B.; de Silva, Shanaka L.; Jimenez de Rios, Guillermina; Croudace, Ian (10 September 1999). "Effusive eruption of viscous silicic magma triggered and driven by recharge: a case study of the Cerro
Chascon-Runtu Jarita Dome Complex in Southwest Bolivia".
562:
Salisbury, M. J.; Jicha, B. R.; de Silva, S. L.; Singer, B. S.; Jimenez, N. C.; Ort, M. H. (21 December 2010). "40Ar/39Ar chronostratigraphy of
Altiplano-Puna volcanic complex ignimbrites reveals the development of a major magmatic province".
120:
Geochemical analysis led de Silva (1994) to suggest that they may be the latest eruptive cycle of the APVC, either as part of a reactivation or waning of that system. Pastos
Grandes is the source of two major ignimbrites, the 8.1
203:
Cerro
Chascon is formed from a cicle of lava flow lobes with a central plug with a diameter of 200 metres (660 ft). Explosive activity occurred before the dome formation and generated a 1 metre (3 ft 3 in) thick
215:
beneath the dome. The lava dome has a volume of 5 cubic kilometres (1.2 cu mi) with a maximum altitude of 5,190 metres (17,030 ft). Its surface is covered by mounds (20 metres (66 ft) high) of presumably
64:
Accompanied with little explosive activity on the main dome Cerro
Chascon, it contains ten lava domes arranged in a chain. Located in the floor of the Pastos Grandes caldera, these domes were erupted after injection of
231:, considering that it lacks any indication of surface flow. The two southernmost domes of the southern group have similar shapes to Chascoso and Pabelloncita. However the second southernmost dome is accompanied with an
341:
and influenced by local lakewaters. In the southern domes, some time occurred between the formation of the andesitic magmas by mixing and the eruption. Both andesitic and rhyolitic magmas were simultaneously extruded.
200:
consistent with the regional trends but may also be influenced by the Pastos
Grandes caldera structure. The arid climate of the area has impeded erosion in the area, leaving the volcanic complex relatively unaltered.
447:
de Silva, S. L.; Self, S.; Francis, P. W.; Drake, R. E.; Carlos, Ramirez R. (1994). "Effusive silicic volcanism in the
Central Andes: The Chao dacite and other young lavas of the Altiplano-Puna Volcanic Complex".
305:
Petrology indicates that the andesitic lavas of the southern domes are derived from the more silicic magmas by addition of more mafic andesites. Conversely, the northern dome magmas formed by
117:
eruptions took place covering an area of 70,000 square kilometres (27,000 sq mi) triggered by the formation of melts deep in the crust and their subsequent rise to the upper crust.
125:
Sifon and the 5.3 mya
Chuhuilla ignimbrite, as well as the 3.1 mya Cerro Juvina ignimbrite shield on the northern caldera flank. The eruption of this complex may have been formed by a
18:
408:"Timescales of large silicic magma systems: implications from accessory minerals in Pleistocene lavas of the Altiplano-Puna Volcanic Complex, central Andes"
667:
227:
and central depressions. The much smaller Cerro Guichi (6 metres (20 ft) high and 25 metres (82 ft) long) may be an exposed
171:
140:
266:
contents ranges from 35% by volume in dacite and 48% by volume of rhyolite. In the northern group these are primarily composed from
238:. The rest of the domes contain a silicic core with surrounding andesitic flows. The domes become less andesitic towards the north.
306:
69:
magmas in the deep less than 100,000 years ago. The largest dome has a volume of 5 cubic kilometres (1.2 cu mi).
89:
this complex is part of the young surface expression of the APVC and may indicate the future location of a caldera.
657:
596:
Evolution of the Cerro
Chascon-Runtu Jarita Complex in Southwest Bolivia: Implications for Silicic Dome Formation
351:
102:
58:
662:
254:
origin, and are highly viscous with large difference between two magma types. The lava domes are formed from
101:
caldera, but it may not be part of that caldera complex proper. The lava dome complex is part of the
635:
599:
290:
components. They contain a rhyolitic core surrounded with andesitic lavas that contains primarily
81:
named Runtu Jarita whose largest member is named Cerro Chascon. This chain is comparable with the
640:
615:
415:
607:
54:
82:
407:
337:
when the injection of new magmas led to eruption. The eruptions of Chascon initially were
8:
262:
in the north. The dacites are crystal rich and some lavas show evidence of magma mixing.
333:
magmas in the magmatic system. Presumably, the magmas were in the process of forming a
318:
371:
572:
542:
508:
457:
223:
Morro Chascoso and Pabelloncita Loma are cone shaped domes with blocky slopes with
338:
630:
376:
326:
126:
98:
317:
The lava domes were erupted between 89,000-94,000 years ago. In Runtu Jarita,
651:
251:
186:
173:
155:
142:
33:
20:
356:
512:
547:
531:"Preeruptive magma viscosity: An important measure of magma eruptibility"
530:
366:
294:
phenocrysts. Temperatures of 926–1,000 °C (1,699–1,832 °F) for
291:
110:
361:
263:
122:
114:
86:
461:
576:
381:
283:
271:
247:
235:
232:
228:
209:
78:
50:
497:
105:, an igneous province located in the Central Andes. During the Late
322:
299:
267:
255:
212:
295:
275:
220:
origin, with sand trails eroded from the mounds separating them.
106:
282:. The southern group rocks have similar petrologies, but are of
334:
279:
259:
217:
205:
97:
The lava domes are contained within the moat and floor of the
330:
309:
with the most evolved components being erupted explosively.
287:
224:
66:
561:
85:
in the United States. Together with other lava domes like
57:. It is part of the more recent phase of activity of the
446:
329:. The eruption may have been caused by the injection of
298:lava and 625–727 °C (1,157–1,341 °F) for
555:
493:
491:
325:has yielded ages of 88,000±4,000 to 97,000±2,000
649:
489:
487:
485:
483:
481:
479:
477:
475:
473:
471:
442:
440:
438:
436:
434:
432:
53:located inside, but probably unrelated to, the
524:
522:
468:
401:
399:
397:
429:
519:
394:
546:
528:
650:
565:Geological Society of America Bulletin
593:
529:Takeuchi, Shingo (5 October 2011).
405:
312:
13:
587:
137:The volcanic complex extends from
14:
679:
246:The lavas of this complex are of
77:The complex is a chain of seven
535:Journal of Geophysical Research
450:Journal of Geophysical Research
352:Altiplano-Puna volcanic complex
103:Altiplano-Puna volcanic complex
59:Altiplano-Puna volcanic complex
668:Volcanoes of Potosí Department
1:
387:
241:
132:
7:
345:
10:
684:
307:fractional crystallization
302:lava have been estimated.
92:
72:
47:Cerro Chascon-Runtu Jarita
594:Watts, Robert W. (1995).
270:with minor components of
636:Global Volcanism Program
600:Indiana State University
286:composition and contain
641:Smithsonian Institution
616:Oregon State University
612:volcano.oregonstate.edu
501:Bulletin of Volcanology
416:Oregon State University
658:Pleistocene lava domes
208:deposit composed from
55:Pastos Grandes caldera
513:10.1007/s004450050274
34:21.88389°S 67.90500°W
663:Landforms of Bolivia
548:10.1029/2011JB008243
39:-21.88389; -67.90500
412:ScholarsArchive@OSU
183: /
152: /
30: /
319:Argon-argon dating
462:10.1029/94JB00652
372:Corral de Coquena
258:in the south and
187:22.033°S 67.817°W
156:21.883°S 67.900°W
83:Mono-Inyo craters
675:
644:
626:
624:
622:
603:
581:
580:
577:10.1130/B30280.1
571:(5–6): 821–840.
559:
553:
552:
550:
526:
517:
516:
495:
466:
465:
444:
427:
426:
424:
422:
406:Tierney, Casey.
403:
313:Geologic history
198:
197:
195:
194:
193:
192:-22.033; -67.817
188:
184:
181:
180:
179:
176:
167:
166:
164:
163:
162:
161:-21.883; -67.900
157:
153:
150:
149:
148:
145:
49:is a complex of
45:
44:
42:
41:
40:
35:
31:
28:
27:
26:
23:
683:
682:
678:
677:
676:
674:
673:
672:
648:
647:
631:"Cerro Chascon"
629:
620:
618:
606:
590:
588:Further reading
585:
584:
560:
556:
527:
520:
496:
469:
445:
430:
420:
418:
404:
395:
390:
348:
339:phreatomagmatic
315:
244:
191:
189:
185:
182:
177:
174:
172:
170:
169:
160:
158:
154:
151:
146:
143:
141:
139:
138:
135:
95:
75:
38:
36:
32:
29:
24:
21:
19:
17:
16:
12:
11:
5:
681:
671:
670:
665:
660:
646:
645:
627:
604:
589:
586:
583:
582:
554:
518:
507:(4): 241–264.
467:
428:
392:
391:
389:
386:
385:
384:
379:
377:Pastos Grandes
374:
369:
364:
359:
354:
347:
344:
314:
311:
243:
240:
134:
131:
99:Pastos Grandes
94:
91:
74:
71:
9:
6:
4:
3:
2:
680:
669:
666:
664:
661:
659:
656:
655:
653:
642:
638:
637:
632:
628:
617:
613:
609:
605:
601:
597:
592:
591:
578:
574:
570:
566:
558:
549:
544:
540:
536:
532:
525:
523:
514:
510:
506:
502:
494:
492:
490:
488:
486:
484:
482:
480:
478:
476:
474:
472:
463:
459:
456:(B9): 17805.
455:
451:
443:
441:
439:
437:
435:
433:
417:
413:
409:
402:
400:
398:
393:
383:
380:
378:
375:
373:
370:
368:
365:
363:
360:
358:
355:
353:
350:
349:
343:
340:
336:
332:
328:
324:
320:
310:
308:
303:
301:
297:
293:
289:
285:
281:
277:
273:
269:
265:
261:
257:
253:
252:calc-alkaline
249:
239:
237:
234:
230:
226:
221:
219:
214:
211:
207:
201:
196:
165:
130:
128:
124:
118:
116:
112:
108:
104:
100:
90:
88:
84:
80:
70:
68:
62:
60:
56:
52:
48:
43:
634:
619:. Retrieved
611:
595:
568:
564:
557:
538:
534:
504:
500:
453:
449:
419:. Retrieved
411:
357:Cerro Chanka
316:
304:
245:
222:
202:
136:
119:
96:
76:
63:
46:
15:
621:29 November
421:26 November
367:Chillahuita
292:plagioclase
190: /
159: /
111:Pleistocene
37: /
652:Categories
388:References
362:Cerro Chao
264:Phenocryst
115:ignimbrite
87:Cerro Chao
79:lava domes
51:lava domes
25:67°54′18″W
22:21°53′02″S
608:"Chascon"
382:Tocorpuri
284:rhyolitic
272:amphibole
248:potassium
242:Petrology
236:lava flow
233:andesitic
229:intrusion
210:rhyolitic
133:Structure
346:See also
323:sanidine
300:rhyolite
268:feldspar
256:andesite
218:diapiric
213:obsidian
113:, large
541:(B10).
296:dacitic
276:biotite
178:67°49′W
175:22°02′S
147:67°54′W
144:21°53′S
107:Miocene
93:Origins
73:Geology
335:pluton
280:quartz
260:dacite
250:-rich
206:pumice
331:mafic
288:mafic
225:talus
67:mafic
623:2015
423:2015
278:and
127:dyke
573:doi
569:123
543:doi
539:116
509:doi
458:doi
321:on
168:to
123:mya
654::
639:.
633:.
614:.
610:.
598:.
567:.
537:.
533:.
521:^
505:61
503:.
470:^
454:99
452:.
431:^
414:.
410:.
396:^
327:BP
274:,
129:.
61:.
643:.
625:.
602:.
579:.
575::
551:.
545::
515:.
511::
464:.
460::
425:.
109:-
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.